North and South Korea have renewed talks on reopening their jointly run Kaesong industrial zone, one of the last remaining symbols of cross-border reconciliation.

North and South Korea began talks Wednesday on reopening a jointly run industrial zone, with tensions running high over the shuttered complex which is seen as the last remaining symbol of cross-border reconciliation.

South Korean delegates met their Pyongyang counterparts in North Korea for the sensitive meeting aimed at restarting the Kaesong complex's mothballed factories. The two sides remain far apart over who was to blame for the closure.

The fresh talks follow a rare weekend meeting in which the two nations agreed in principle to reopen Kaesong, which shut down three months ago as relations between the frosty neighbours hit crisis point.

A vehicle convoy of about 130 South Korean delegates, support staff and factory owners passed through the heavily fortified de-militarised border zone that underscores the ever-present tension between two nations, which remain technically at war. Their 1950-53 conflict ended in a ceasefire rather than a peace treaty.

The vehicles were outfitted with bright red flags, following key border rules aimed at preventing an accidental shooting.

The once-buzzing industrial zone — which had previously remained largely resilient to turbulence in relations — had the air of a ghost town, with factories and convenience stores shuttered and dark, traffic signals off and North Korean workers plucking overgrown weeds from the sidewalk outside the 15-storey building where the talks were being held.

As the talks got underway, South Korea's chief delegate Suh Ho hailed the meeting as "one of the first steps towards trust".

"I hope that we will be able to exchange good ideas to revive the Kaesong industrial complex in a progressive way," he told reporters.

His North Korean counterpart, Pak Chol-Su, had more immediate concerns, saying: "I am really worried about the state of the factories' machines".

The Kaesong complex, which was built in 2004, sits about 10 kilometres (six miles) inside North Korea. The South Korean-funded site, built as part of a diplomatic bid to improve cross-border relations, was a key source of hard currency for the impoverished North.

In April Pyongyang withdrew its 53,000 workers from the 123 Seoul-owned factories at the complex, citing military tensions and the South's hostility towards the North.

Seoul withdrew managers from most of the operations in early May.

The South now wants firm safeguards from the North against shutting Kaesong down unilaterally and to keep the estate insulated from Pyongyang's whims.

This would be a bitter pill for the North to swallow as it means it would accept full responsibility for the April closure.

The South also wants a pledge to safeguard uninterrupted movement in and out of the complex, as well as compensation for losses stemming from the suspension, a demand that the North is unlikely to accept.

"We will not accept circumstances reverting back to the way they were before the crisis," South Korean Unification Ministry spokesman Kim Hyung-Suk told reporters in Seoul on Tuesday.

The latest round of talks follow months of friction and threats of war by Pyongyang after its February nuclear test attracted tougher UN sanctions, further squeezing its struggling economy.

At the end of gruelling 15-hour talks, the two sides said in a joint statement Sunday that they had agreed to let South Korean firms restart their shuttered plants at the complex when conditions are ripe.

The statement was viewed as a crucial step forward in winding down the months of high tension.

It was unclear how long Wednesday's talks would last.

On Tuesday, more than 20 visitors from the South, including government officials and workers, visited the complex.

Some factory bosses have threatened to withdraw from the complex, complaining they have fallen victim to political bickering between the two rivals.